Canadian Pat. No. 159,552 dated Dec. 15, 1914, in the name of John Gorrien, describes an automatic damper of the above-noted type and for the same purpose. Because of its construction, the damper arrangement of this patent cannot produce an equal closing of the damper for all wind direction and, therefore, the chimney draft cannot be kept sufficiently constant, not only under varying wind velocities but also under varying wind directions.